Can't help you much on float trips as I've never done it. I have fished the Lehigh for over 40 years, wading. My experience has been that any flow above 1000 ( at white haven) is difficult fly fishing. Boating is probably much easier. A floating sweet spot for that section is most likely 750 cfm or so.
As for streamers, stay with black or peacock wooly buggers, white or yellow zonkers, and a black dace. You need not be fancy here. Sizes 8-10 are fine.
Flies are your typical NEPA variety. Black and brown stone fly (14), Quill Gordon (12), Hendrickson/red quill (14,16), Grey fox (14,16), March Brown (10), Lt. Cahill (14,16), isonychia (12), BWO (18-14), caddis tan, green, Grey, black, (18-14), yellow and green Sally (14). Pheasant tails, green caddis larvae, grey soft hackle, March brown wet, hares ear, frenchies, and lightning bug round out the mix.
Concentrate around protruding rocks, foam and shade lines, back eddies and "whirlpools ". Also if floating, the majority of feeders from the west are AMD. Those on eastern shore are clean for the most part ( below JT you are good on both sides).
Fish on opposite bank of AMD streams for about 1/4to 1/2 mile below depending on flows as the fish will concentrate on clean water side.
Please be careful when floating or wading. Don't be daring and i would stay off if flows are above 2500 at White Haven. YMMV depending on size of your testicles.
